Stoker



4 Sheet`s Sheet l Sept 30, 1941- J. s. BENNETT STOKER Filed DEC. 5l, 1937 Sept. 30,l 1941 J. s. BENNETT STOKER Filed Dec. 3l, 1937 4 Sheets-Sheet 2 I Seht- 30, 1941- J. s. BENNETT 2,257,588

STOKER File@ Dec. s1, 1937 4 shedssheet s Sept. 30, 1941. 1 s. BENNETT 2,257,588 l sToKER Filed DBC. 31, 1937 4 Sheets-Sheet 4 il" lili, l,

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Patented Sept. 30, 1941 STOKER Joseph S. Bennett, Merion, Pa., assigner to American Engineering Company, Philadelphia, Pa., a corporation of Pennsylvania Application December 31, 1937, Serial No. 182,763

9 Claims.

This invention relates to stokers, and more particularly to stokers of the fluid cooled type.

One object of the present invention is to provide a generally improved Stoker of the uid cooled type.

Another object is to provide improved tuyre 'constructions for stokers of the stated character which not only effectively distribute air for combustion in the fuel bed, but which are so disposed as to be effectively cooled by uid cooling means, thereby insuring longevity of service.

Other and further objects will become apparent as the description of the invention progresses.

Of the drawings:

Fig. 1 is a longitudinal sectional View taken through one of the retorts of a Stoker of the inclined grate, multiple retort, underfeed type, showing the fluid cooling system associated therewith.

Fig. 2 is a sectional view of one of the stoker tuyre rows, taken substantially along line 2 2 of Fig. 1.

Fig. 3 is a perspective view of one of the tuyre blocks secured t'o one of the tubes shown in Fig. 2.

Fig. 4 is a perspective View of the tuyre block shown in Fig. 3 in inverted position.

Fig. 5 is a perspective view of one of the tuyre blocks secured to the other of the tubes shown in Fig. 2.

Fig. 6 is a perspective View of the tuyre block shown in Fig. 5 in inverted position.

Fig. 'l is a fragmentary side view of a tuyre assembly of an alternative construction, parts of which are broken away to show the structure of the interior thereof, and of which parts are shown in section.

Fig. 8 is a sectional View taken substantially along line 8--8 of Fig. 7.

Fig. 9 is a perspective view of one of the tuyre blocks disposed between the tubes shown in Fig. 8, a portion of the end of which being broken away to show one of the air passages provided therein.

Figs. 10 and 11 are perspective views of the tuyre blocks disposed at the sides of the tubes shown in Fig. 8.

Fig. 12 is afragmentary side view of another embodiment of the present invention, with parts broken away to show the construction of the interior thereof and with certain parts shown in section.

Fig. 13 is a sectional View taken substantially along line I3-I3 of Fig. 12.

Fig. 14 is a longitudinal sectional View of a f further embodiment of the present invention taken substantially along line Ill-I4 of Fig. 15.

Fig. 15 is a transverse sectional view taken substantially along line I5--I5V of Fig. 14.

Fig. 16 is a transverse sectional View showing a still further embodiment of the present. invention, and

Fig. 17 is a side View partly in section and with certain parts removed to show the structure of they tuyre blocks, said view being taken substantially alongline I l-I 1 of Fig. 1b.v

Referring to the drawings,.the numeral I indicates a stoker of the inclined grates, multiple retort, underfeed type, consisting of alternately disposed retorts 2, and tuyre rows 3. Fuel from hoppers 4, disposed exteriorly of the front Wall 5 of the furnace, is fed to the retorts by feeding rams B, driven by any suitable power mechanism 'I. Fuel is fed along each retort by a series of pushers 8 to a dead plate 9 disposed at the lower end thereof from which it is fed into an ash pocket IIJ disposed at the rearmost end of the Stoker. The pushers 8 are reciprocated by any suitable link and lever mechanism indicated generally at Il, and operatively connected to the power mechanism 'I.

The sides of the retorts are bounded by substantially vertical walls which consist of longitudinally extending side platesl I2 and I3, Figs. 1 and 2, and a series of side tuyre plates I4 and I5, secured respectively to side plates I2 and I3. Mounted-respectively on the side tuyre plates I 4 and I5 are tuyre members I 6 and I'I, which, as shown in Fig. 2, are provided with semi-circular recesses I 8 and I9 respectively, for receiving fluidA conducting tubes 2U and 2|. The tubes2ll and 2I of each tuyre row 3 extend downwardly over the entire length thereof, and then are bent downwardly and forwardly, as shownv at 22, and form a portion of the front wall of ash pocket Ill.- The lower ends of these tubes terminate in a header 23. The front end of tubes 20 and 2| are bent upwardly, as shown at 24, and extend vertically in closel contact with the interior of front wall 5, and terminate at their upper ends in a boiler, not shown. Also extending upwardly from header 23 and lying between each pair of tubes 20 and 2| are one or more tubes 25. These tubes extend in substantially parallel relation with the lower portions of tubes 20 and 2|, and also form a portion of the front wall of ash pocket I0 until reaching the upper end thereof, when they are bent for- Wardly so as to extend beneath and in intimate contact with dead plates 9. The forward ends of tubes 25 then terminate in a header 26 disposed beneath the stolzer. Header 23 is connected to the boiler by downtake connection 21, While header 26 is connected to the boiler by an uptake connection 28. Draft air is supplied to the furnace from a plenum chamber 29 disposed beneath the stoker, which is supplied with air under pressure by any suitable fan or blower mechanism (not shown) through a passage 30. The lower and rearwardly disposed end of the stoker receives air from a sub-plenum chamber 3I, which communicates With chamber 29 through an opening 32, the size of the latter of which may be regulated by means of a damper 33.

Each side tuyre plate I4 is provided with an apertured flange 34 through which bolts 35 extend, and a shoulder 36 which rests upon the upper edge of side plate I2. Thus, to secure a side tuyre plate in position it is only necessary to align the apertures in flange 34 thereof with tapped openings in plate I2, and to then secure the plate in position. Each tuyre plate I is likewise provided with an apertured flange 31, and a longitudinally extending shoulder 38 which rests upon the upper edge of side plate I3. Bolts 39 are provided to rigidly secure plate I5 to plate I3.

The upper end of tuyre plate I4 is provided with a longitudinally extending projection 40 which interlo'cks with a groove 4I provided in the laterally extending portion 42 of tuyre member I6. Tuyre member I6 is drawn into intimate contact with tube 20 by means of a pair of bolts 43, welded or otherwise secured to the under side of the tube 'and arranged in spaced relation therealong. These bolts are provided With screw threads at their lower ends and are adapted to extend through apertures 44 'provided near the ends of tuyre member I6, as shown more particularly in Figs. 3 and 4, and nuts 45 may then draw the tuyre member into contact with thev tube. IIfhe under side of each tuyre member I6 has also provided therein a longitudinally extendving slot 46, which forms an inlet passage for draft air. This slot communicates with a series of grooves 41 provided around one side of lthe semi-circular portion I8 of each tuyre member I6. Thus, when a tuyre member I6 is drawn into intimate contact with tube 20, contact is made only at spaced points therealong, the grooves provided in the semi-circular surface thereof providing va series of passages through "which draft air may pass into the fuel bed. The

laterally extending portion 42 of each tuyre block I6 has also provided therein a series of passages48, through Which draft air may enter the fuel bed.

The tuyre members I1 are generally similar in construction to tuyre members I6 and are shown more particularly in Figs. 5 and 6. This construction also has a laterally extending portion 49 provided with a longitudinally extending groove 50 at the lower end thereof which seats over the longitudinally extending projection 5I provided Yat the upper end of side tuyre plates I5. Tuyre members I1 are also secured to tube 2I by means of bolts 52, secured to tube 2I by welding or by 'any other suitable'method of fastening. Bolts 52 are adapted to extend through apertures 53 provided near the ends of tuyre member I1 and nuts 54 engaging the lower ends of these bolts draw the tuyre member into intimate contact With tube 2|. Each tuyre member I1 is also provided with a longitudinally extending slot 55 at the lower side thereof through which draft air may pass. This slot communicates with a series of grooves 56 provided around one side of the semi-circular portion I9 and through which draft air passes to the fuel bed When the tuyre member I1 is assembled on tube 2I. The laterally extending portion 49 of each tuyre member I1 is also provided with a series of passages 51 through which draft air may also pass into the fuel bed. Draft air also enters the fuel bed through passages 58 and 59 provided respectively in side tuyre members I4 and I5.

Referring to Fig. 2, it will be noted that when the tuyre Imembers I6 and I1 are assembled on tubes 2D and 2| respectively, a space 60 is provided between the inner ends thereof through which draft air may also enter the fuel bed. It Will be noted that the inner side of th tuyre members I6 extend slightly higher than the corresponding side of tuyre members I1, and that the inner ends of tuyre members I6 are each provided with'a laterally extending lip 6I which overlaps a portion of the upper inner side of the adjacent tuyre member I1. By this construction a sufficient quantity of air passes into the fuel ybed to effect complete combustion of the fuel and at the same time a partial seal is formed against the passage of siftings into the chamber beneath the Stoker.

To prevent any possible distortion of the tubes 20 and 2l and the tuyre members secured thereto, securing bars 62 are provided. These bars are provided with apertures 63 near each end thereof in alignment with studs 43 and 52. These bars are assembled in position by simply moving the same vertically after aligning the apertures 63 with studs 43 and 52, and are held in position by the nuts 45 and 54, as shown in Fig. 2.

Figs. 7 to l1 inclusive, show a modified construction comprising intermediate tuyre members 64 `and side tuyre members 65 and 66. As shown more particularly in Figs. 8 and 9, each intermediate tuyre member 64 is of angular construction having longitudinally extending arcuate surfaces 61 and 68 which are adapted to engage the inner surfaces of a pair of fluid conducting tubes 69 and 1.6, respectively. The upper surface 1I of tuyre member 64 is disposed slightly above the axes of tubes 69 and 1I), and is provided with a series of steps 12. A series of air passagesv13 is provided in the upper surface 1I of each tuyre member E4. Tuyre members 64 are held in intimate contact with tubes 69 and 10 by means of stud bolts 14 and 15, depending from the lower sides of tubes 69 and 10 respectively. Retaining bars 16 are also secured to bolts 14 and 15, and are held in position together with tuyre members 54 by means of nuts 11 and 18, engaging the lower threaded ends of said bolts.

Each tuyre member 65 comprises a vertical portion 8U terminating at its upper end in an offset arcuate .portion 8|, the latter of which engages the outer side of tube 69. The ends of arcuate portion 3I terminate in a pair of extended arcuate portions 82 and 83, each of which having an aperture 84 provided therein. These apertures are adapted to receive studs B5 welded or otherwise secured to tube 69 to prevent lateral movement of tuyre members 65. These studs also act as guides to insure proper contact between tube 69 and arcuate portion 8| during assembly of tuyre members 65 in position. The lower edge 86 of each tuyre member 65 is slightly inclined and engages the correspondingly inclined upper surface of a. wedge member 81, the lower surface of which rests upon an inwardly extending flange 88 of the side plate 89 of the tuyre chamber. A bolt 90, secured at one end near the upper end of side plate 89, loosely receives wedge B1. The wedge 81 is actuated toward side plate 89 by a nut 9| and washer 92 engaging the threaded inner end of bolt 90. Upon movement of wedge 81 in this manner tuyre member 65 is moved vertically into engagement with tube 69. To assemble a tuyre member 65 in position, it is first moved vertically toward tube 69 after apertures 84 have been brought into alignment with studs 85. Wedge 81 is then actuated by nut 9| to further actuate tuyre member 65 to bring the same into intimate contact with tube 69. As shown more particularly in Fig. 10, a series of grooves 93 are provided in arcuate portion 8| between the end portions 82 and 83. These grooves forni passages for draft air adjacent the tube 69. As shown in Figs. 7 and 11, a series of passages 94 is also provided at the sides of vertical portion 80 ofv each tuyre member 65 through which .draft air may also enter the fuel bed.

Each tuyre member 66 is identical in construction with tuyre member 65. Accordingly, a detailed description thereof is unnecessary. Upon reference to Fig. 8, however, it will be noted that l the tuyre members 66 are secured to tube 10 by means of studs 95, and the bolt and wedge members 96 and 91, respectively.

Figs. 12 and 13 show a further modification of the present invention. This construction also comprises intermediate tuyre members and side tuyre members |0| and |02. Each tuyre member |00 is provided with a pair of arcuate surfaces |03 and |04 which engage the upper inner sides of fluid conducting tubes |05 and |06 respectively. As shown in Fig. 12, each tuyre member |00 has provided therein a series of' air passages |01, through which draft air may pass into the fuel bed. The ends of each tuyre member |00 are provided with enlarged portions |08 and |09 which have provided therein open ended;

recesses ||0 and respectively, for receiving securing bolts I2 and I3.

The tubes |05 and |06 extend lengthwise of the tuyre chamber and rest upon the concave portions ||4 and 5 of supporting brackets H6..

The lower ends of brackets I6 rest upon inwardly extending anges ||1 and ||8 respectively of side plates ||9 and |20. Locking pins |2| and |22 extending through flanges ||1 and ||8 respec tively, secure the brackets ||6 against lateral movement. Thus, to assemble the tuyre blocks |00 in position on tubes |05 and |06, it is only necessary to place them end to end along the length of said tubes, and to secure the abutting ends of pairs of tuyre blocks l|00 in position in intimate contact with the tubes by means of nuts engaging the upper threaded ends of bolts ||2 and ||3. It will be noted that slots |26 are provided at the ends of each tuyre block |00,

which receive the Shanks of bolts ||2 or 3 so that the tuyre blocks may be moved into abutting relation with the next tuyre block of the series. Bolts ||2 and ||3 may be secured to the supporting brackets |6 by a pair of lock nuts |23, as shown in Figs. 12 and 13.

Each end tuyre block |0| comprises a substantially vertical portion |21 which rests upon the upper edge of side plate||9. The upper right hand end (Fig. 13) of portion |21 terminates in an arcuate portion |28 which engages the left hand side of tube |05. A bolt receiving recess |29 is provided at each end of tuyre member' |0| consisting of a reduced portion |30 for receiving the shank of a bolt |3|, and an enlarged portion |32 for receiving a locking nut |33. Vertical portion |21 has also provided therein a series of passages |34 through which draft air may pass into the fuel bed. These passages may diverge toward the discharge end thereof to reduce the velocity of the air as it approaches the discharge end. To assemble the tuyre blocks |0| on the stoker they are simply placed in abutting relation, as shown in Figs. 1 and 2, and the bolts |3| are then passed through apertures provided 4in brackets ||6, and the recesses |29. The lock nuts |33 then draw the blocks into intimate 'contact with tubes |46 and |41.

contact with tube |65.

Tuyre block |02 is similar in construction to tuyre block |0|, and also comprises a vertical portion |34' which rests upon the upper edge of side plate |20 and an arcuate portion |35 which engages the right hand side of tube |06. Lock bolts |36 are provided to secure the blocks |02 to brackets ||6 and in intimate contact with tube |06. Tuyre blocks |0| and 02 are respectively provided with longitudinally extending lips |31 and |38 to facilitate the assembly of said blocks on the Stoker.

Figs. 14 and 15 disclose a still further modification of the present invention. This construction also consists of a series of intermediate tuyre blocks |40 and a pair of end tuyre blocks |4| and |42.

Each intermediate tuyre block |40 is held in position by an individual clamp block |43, thus affording a somewhat simplied form of securing means. As shown in Figs. 14 and 15, each tuyre block |40 is provided with arcuate surfaces |44 and which respectively engage the inner sides of a pair of fluid conducting tubes |46 and |41. Depending from the lower side of each tuyre block |40 is a tongue |48, the upper surface |49 of which being inclined and receives the inclined surface of the tongue |5| of clamp block |43.

Each clamp block |43 is provided with arcuate side surfaces |52 and |53 which in assembly engage the lower inner sides of tubes |46 and |41 respectively. Thus, to secure a block |40 in intimate contact with the tubes |46 and |41, the retaining block 43 is moved longitudinally therealong until the tongues |48 and |5| interlock. To effect a tight joint between block |40 and tubes |46 and |41, an impact may be given to the clamp block |43 to wedge block |40 tightly into engagement with the said tubes. Series of grooves |54 are provided in the arcuate surfaces |44 and |45 of each tuyre block |40. These grooves form a series of passages between blocks |40 and tubes |46 and |41, through which draft air may pass to the fuel bed.

Blocks |4| and |42 are similar in construction to blocks 65 and 66, shown in Fig. 8, and therefore need not be described in detail. In this construction also wedges |55 and |56 are employed to urge blocks |4| and |42 respectively, into intimate Studs |51 and |58 engage in apertures provided in blocks |4| and |42 to prevent lateral displacement of the blocks, as well as to guide them in their move- -nient toward the tubes.

Figs. 16 and 1'? show a still further modification ofthe present invention. In this construction tuyre blocks |60 and |6| of the toggle type are employed intermediate the tubes |62 and |63, while end tuyre blocks |64 and |65 are disposed between tubes |62 and |63 respectively, and the corresponding side plates of the tuyre chamber. Tuyre blocks |60 and |6| are provided with arcuate surfaces |66 and |61 which respectively engage the inner surfaces of tubes |62 and |63. Block |60 is provided with a longitudinally extending projection |68, which engages in a correspondingly shaped recess |69 provided near the upper end of block |6| The lower ends of blocks |60 and |6| are provided with extensions |10 and |1| having aligned apertures provided therein for receiving the ends of an extensible bolt |12, having an operating nut |13 provided thereon. Thus, to urge blocks |60 and |6| into intimate contact with tubes |62 and |63, bolt |12 is simply extended by operation of nut |13, whereby the blocks pivot at the joint made between projection |68 and recess |69, thereby bringing the arcuate surfaces |66 and |61 respectively thereof into intimate Contact with tubes |62 and |63. The arcuate surfaces |66 and |61 of blocks |60 and |6| are provided with a series of grooves |14 which, when the blocks are assembled in position on the tubes, form a series of passages through which draft air may enter the fuel bed. Passages may also be formed in tuyre block 6 as shown at |15, adjacent the joint between projection |68 and groove |69 to permit additional air to enter the fuel bed if it is so desired. To prev-ent distortion of tubes |62 and |63 securing bars |16 are provided. These bars are secured in any suitable manner to bolts |11 and |18, rigidly secured to tubes |62 and |63 respectively.

The end tuyre blocks |64 and |65 are similar in construction to the tuyre blocks shown in Fig. 8, and accordingly a detailed description thereof is unnecessary. In this construction it will be noted that wedges |19 are employed to urge the blocks into intimate contact with the tubes. Studs |86 and |8| secured to the tubes are also provided to prevent lateral movement of the end blocks |64 and |65, and also to assist in guiding the blocks in their movement into contact with the tubes.

From the foregoing description of the various embodiments of the present invention it is seen that simplified, as well as highly eilicient constructions have been provided. Each tuyre construction is made up of a pair of tubes and different fo-rms of tuyre block constructions mounted on said tubes in such a manner as to expose a portion ofthe surface thereof to the heat of the furnace. These tuyre blocks are both effectively cooled by contact with the fluid `conducting tubes, as well as by the draft air passing therethrough, and as a result longevity of service is assured even under the most severe conditions of operation. 'I'hese novel arrangements of tuyre blocks are also so constructed as to makeit possible to renew them if necessary, without disturbing adjacent parts.

While the embodiments herein shown and described are admirably adapted to fulfill the objects primarily stated, it is to be understood that it is not intended to limit the invention to these embodiments since it may be embodied in other forms, all coming within the scope of claims which follow.

What is claimed is:

1. A fiurfnace Stoker, comprising alternately disposed retorts and tuyre rows, each of said tuyre rows consisting of a pair of spaced side walls, a tuyre-assembly mounted on said side walls, said tuyre assembly consisting of a pair of longitudinally extending tubes, a row of tuyre members secured beneath each of said tubes, lateral extensions on said tuyre members, coacting means on said tuyre members and tubes for holding said tuyre members in position and interlocking means on said lateral extensions vand said side walls for supporting, as wellas preventing lateral distortion of said tubes and tuyre members.

2. A furnace stolzer, comprising alternately disposed retorts and tuyre rows, each of said tuyre rows consisting of a pair of spaced side walls, a tuyre assembly mounted on said side walls, said tuyre assembly comprising a pair of longitudinally extending tubes, a row of tuyre members secured beneath each of said tubes, each of said tuyre members having a longitudinally extending inlet passage, and a series of grooves communicting with said inlet passage, said grooves lying adjacent said tubes when `the tuyre members are assembled thereon, thereby forming a series of passages for draft air, a lateral extension provided on each of said tuyre members for supporting the same in position, and means for drawing said tuyre members into intimate contact with said tubes.

3. A furnace stoker, comprising alternately disposed retorts and tuyre rows, each of said tuyre rows consisting of a pair of' spaced side walls, a tuyre assembly mounted on said side walls, said tuyre assembly comprising a pair of longitudinally extending tubes, stud bolts secured to the lower sides of said tubes in spaced relation therealong, a row of tuyre members disposed beneath each of said tubes and secured Ito the latter by said stud bolts, lateral extensions provided on said tuyre members, side tuyre plates secured to each of said side walls, interlocking means on said lateral extensions and side tuyre plates, retaining means secured to said stud bolts to prevent distortion of said tubes, and each of said tuyre members having a series of passages provided therein through which draft air may pass.

4. A furnace stoker, comprising alternately disposed retorts and tuyre rows, each of said tuyre rows consisting of a pair of spaced side walls, a tuyre assembly mounted on said side walls, said tuyre assembly comprising a pair of longitudinally extending tubes, a row of tuyre members secured beneath each of said tubes, lateral extensions provided on said tuyre inembers vfor supporting said tuyre members and tubes in position on said side walls, the inner surface of one row of tuyre members being spaced from the inner surface of the adjoining row `of tuyre members thereby providing a Dassage for draft air, and a lateral projection extending from each of the tuyre members of one of said rows and overlying the upper surface of the tuyre members of the adjacent row for preventing fuel siftings from passing between said rows of tuyre members.

5. A furnace Stoker comprising alternately disposed retorts and tuyre rows, each of said tuyre rows consisting of a pair of spaced walls, a tuyre assembly mounted on said walls, said tuyre assembly comprising a pair of longitudinally extending tubes, a row of intermediate tuyre members disposed between said tubes, said tuyre members having an arcuate face at each side thereof conforming with the curvature of said tubes, means for urging said tuyre members into contact with said tubes, a row of said tuyre members disposed between one of said tubes and one of said side walls, a second row of said tuyre members disposed between the other of said tubes and the other of said side walls, and adjustable means for urging said side tuyre members into intimate contact with said tubes.

6. A furnace stoker comprising alternately disposed retorts and tuyre rows, each of said tuyre rows consisting of a pair of spaced walls, a tuyre assembly mo-unted on said Walls, said tuyre assembly comprising a pair of longitudinally extending tubes, a roW of intermediate tuyre members disposed between said tubes, each of said intermediate tuyre members having a pair of concave faces adapted to engage the inner surfaces of said tubes, stud bolts depending from said tubes for securing said intermediate tuyre members in intimate contact with said tubes, a row of side tuyre members disposed between one of said tubes and one of said side walls, each of said side members having an arcuate face adapted to engage the outer side of said tube. means for urging said side tuyre members into intimate contact with said tube, and means depending from said tube interlocking with said side tuyre members for preventing lateral displacement oi the latter, a second row of side tuyre members disposed betweeny the other of said tubes and the other of said side walls, each of said last mentioned side tuyre members having an arcuate face provided thereon adapted to engage the outer side of said last mentioned tuyre members into intimate contact with said last mentioned tube, and each of said tuyre members having passages provided therein through which draft air may pass.

7. A furnace Stoker, comprising alternately disposed retorts and tuyre rows, each of said tuyre rows consisting of a pair of spaced Walls, a tuyre assembly mounted on said Walls, said tuyre assembly comprising a pair of longitudinally extending tubes, a row of intermediate tuyre members disposed between said tubes, each of said intermediate tuyre members having a pair of concave faces adapted to engage the inner surfaces of said tubes, stud bolts depending from said tubes for securing said intermediate tuyre members in intimate contact With said tubes, a row of side tuyre members disposed between one of said tubes and one of said side walls, each of said side members having an arcuate face adapted to engage the outer side of said tube, means for urging said side tuyre members into intimate contact with said tube, and means depending from said tube interlocking with said side tuyre members for preventing lateral displacement of the latter, a second row oi side tuyre members disposed between the other of said tubes and the other of said side walls, each of said last mentioned side tuyre members having an arcuate face provided thereon adapted to engage the outer side of said last mentioned tube, means for urging said last mentioned tuyre members into intimate contact with said last mentioned tube, each of said tuyre members having passages provided therein through which draft air may pass, and retainer bars secured to said first mentioned studs for preventing lateral displacement of said tubes.

8. A tuyre block adapted for assembly on a tube of a iiuid cooled Stoker, said tuyre block comprising an elongated body structure having an arcuate tube receiving portion, and a laterally extending supporting portion, said arcuate portion having a series of grooves provided therein forming a series of air passages when the tuyre block is assembled on said tube, and said supporting portion having a series of passages through which additional draft air may pass.

9. A side tuyre member adapted for assembly on a stoker of the fluid cooled type, said tuyre member comprising an elongated body structure having a transversely inclined lower edge adapted to engage operating means, and an arcuate tube receiving portion at the other end thereof, said arcuate portion having a series of grooves provided therein forming passages for draft air when said tuyre member is assembled on the Stoker and apertures for receiving projections provided on the tube to prevent lateral movement of said tuyre member, and said body structure having a series of air passages provided at the side thereof through which additional draft air may pass.

JOSEPH S. BENNETT. 

